Let me second Tom Piatak.  I think the best way to start appreciating Ella is by getting (off iTunes, for example) the various songbooks she recorded–Cole Porter, Gershwin, Rogers and Hart.  In these she sings mainly straight without a lot of jazzing around.  My wife generally dislikes most jazz (except George Shearing and a few others) but she is always asking me to play the lady with the beautiful voice.